Filling level

Volume percentage of a liquid or solid filling material in a container or vessel.

With respect to cold chamber die casting, the term filling level refers to the shot sleevefilling level. This is understood to mean the percentage by which the shot sleeve is filled after dosing and prior to initiating the injection process. 

In cold chamber die casting, the metal volume required for casting is less than 100% of the available shot sleeve volume, filling levels of between 40 and 60% being usually obtained. The filling level depends on the internal shot sleeve diameter (or the plunger diameter) which needs to be selected according to the given casting conditions and the active shot sleeve length.

The active shot sleeve length is the distance between the plunger and the mold parting plane. Generally, the shot sleeve is dimensioned in such a way that a relatively high filling level is reached in order to keep the air volume inside the sleeve as low as possible, avoiding air inclusions from the slow shot phase.

The correct choice of the changeover point (from slow shot phase to mold filling phase) must primarily be coordinated with the filling level of the shot sleeve. The benefits of a high or low filling level are listed in Table 1.

 

In addition, the filling level is closely linked to the cooling of the metal. For aluminum alloys (Al die casting alloys), Fig. 1 shows that the temperature loss of metal filled into the shot sleeve is the lower, the higher the selected filling level

Literature references:

S. W. Juang, Paper G-T89-043, Transactions 15th International NADCA-Die Casting Symposium, St. Louis, 1989.
F. Faura, J. López, J. Hernández: On the optimum plunger acceleration law in the slow shot phase of pressure die casting machines. Int. Journal of Machine Tools & Manufacture, 41 (2001), p. 173-191.

  • Table 1: Advantages and disadvantages of a high or low filling levels
  • Fig. 1: Influence of the shot sleeve filling level on the metal temperature in the shot sleeve according to S. W. Juang
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